The present invention relates to a timer device capable of setting plural time units by means of switches.
In case of the conventional timer devices of this type, timer circuit means and switches, which move to various positions to set plural time units on the timer circuit means, are housed in a housing, and a time setting knob which is connected to the timer circuit means to render it operative is projected from the outer surface of the housing. A scale plate on which a time scale is displayed is stuck or screwed to that outer surface area of the housing where the time setting knob is projected.
When the time unit is to be changed in the conventional timer device, time unit setting switches housed in the housing must be operated after the back cap of the housing is detached, and while the scale plate is changed. It easily happens, therefore, that a scale plate having a time scale which shows a time unit different from the one set in the timer circuit means by the time unit setting switches is attached to the housing, and the work of correcting this error is troublesome.
If the time unit setting switches are arranged on the outer surface of the housing, the work of setting time units by the switches can be simplified. However, the time unit setting switches arranged on the outer surface of the housing can be easily operated from outside even after a time unit is set. A malfunction is likely to result accordingly.